1. Field of the Invention
The invention relates to octahydro-N-[(trichloromethyl)thio]naphthalenedicarboximides having fungicidal activity which are represented by the general formula ##STR1## where R represents ##STR2## The compounds represented by formula IA, IB and IC respectively are 1,2,3,5,6,7,8,8a-octahydro-4,7-dimethyl-N-[(trichloromethyl)-thio]-1,2-nap thalenedicarboximide; 1,2,3,4,4a,5,6,7-octahydro-2,2-dimethyl-N-[(trichloromethyl)thio]-1,3-meth anonaphthalene-5,6-dicarboximide; and 1,2,3,4,5,6,7,8-octahydro-5,5-dimethyl-N-[(trichloromethyl)thio]-2,3-napht halenedicarboximide.
The invention further relates to fungicidal compositions containing, and to the method of use of, compounds of the formulas IA, IB and IC.
2. Description of the Prior Art
Fungicidal compounds have been employed to combat fungus infections in man and animals, as plant protectants and for the preservation of materials such as wood, leather, and paper. One of the most important applications is in wood preservation, e.g., preservation of boards against blue discoloration and of building timbers against fungus destruction. Fungicides find increasing application in the preservation of paints against primary and secondary fungal attack, e.g., when applied to wooden window frames, and wooden walls in dairies, bakeries and cellars.
Known fungicides are organic mercury compounds, organic tin compounds, pentachlorophenol and dithiocarbamic acid derivatives. Many of these compounds, however, suffer from disadvantages. For example, mercury compounds are very toxic. The organic tin compounds undergo changes under the influence of light and quickly lose their activity. Pentachlorophenol is very volatile and per se, as well as due to accompanying impurities, is very toxic so that its use is banned in several countries. Finally, derivatives of dithiocarbamic acid have the disadvantage that in contact with metals or metal salts such as siccatives, they cause discoloration.
The trichloromethylthio compounds described in U.S. Patent 2,533,770 are good, long acting fungicides whose action is due to the blocking of SH-groups in phosphorylating enzymes, cf, R. G. Owens and H. M. Novotny, Contr. Boyce Thompson Inst., vol. 20, p. 171 (1959). These fungicides are prepared by the reaction of the appropriate dicarboxylic acid imide with trichloromethanesulfenyl chloride. The imides employed as starting materials in this reaction are endomethylene-tetrahydrophthalimide, phthalimide, tetrahydrophthalimide and succinimide. Of the compounds prepared, primarily compounds represented by the formulas II and IV below are encountered as items of trade. ##STR3##
In addition, fluorinated compounds having formulas V and VI below have been developed which display useful properties as fungicidal additives to paints, cf. "Fette, Seifen, Anstrichmittel", vol. 68 (1966) pp. 275-279. ##STR4##
The foregoing identified trichloromethylthio compounds, while being weather-resistant, [cf. B. A. Richardson, B.W.P.A. Annual Convention (1972), Chapter (6), Sapstain Control, P. 9] are very poorly soluble which impairs their fungicidal activity. Thus, Captan (II), owing to its low solubility in paints, is practically ineffective, cf. B. A. Richardson, loc. cit. The solubility of compound IV in petroleum ether is only 0.3%. The low solubility of these compounds makes the preparation of effective fungicidal agents extremely difficult since in order to obtain sufficient activity, the agent should on the average contain about 3% of the active ingredient. Thus, E. Hoffman and A. Saracz found that 1% of compound III is insufficient to prevent blue discoloration, 2 to 3% being required [J. Oil Col. Chem. Assoc., vol. 50 (1967) p. 434].
In order to find a fungicide with high solubility in petroleum hydrocarbons, numerous N-trichloromethylthio compounds have been synthesized and tested for activity and solubility. In these investigations it was found that not all compounds represented by the general formula ##STR5## are active fungicides as disclosed in U.S. Pat. No. 2,553,770. Rather, activity is associated with certain structural features. Thus, the N-trichloromethylthio compounds prepared from anthracene-maleic anhydride adduct, homophthalic anhydride, caryophyllene-maleic anhydride adduct, isoeugenol-maleic anhydride adduct, camphoric anhydride, hexadecylsuccinic anhydride, and many other anhydrides are inactive.